Platycnema. 9 



præapical bristle below; middle tibiæ with a distinct apical spur. 

 Claws and piilvilli small. Wings somewhat broad at base with alula 

 slightly developed and with a large axillary lobe, both with some- 

 what long hairs; discai vein unforked; no posterior cross-vein, and 

 thus no closed discai cell; medial cross-vein rather near base, basal 

 cells of equal length, not small; anal cell longer than basal cells; 

 anal vein reaching margin ; axillary vein indistinct. A stigma present. 

 Costa cihated and with a long bristle at base. Squamulæ quite small. 

 Halteres with the knob large. 



The developmental stages are not known. 



Of the genus there seems to be only one species, also occurring 

 in Denmark. If the doubtful tibiella Zett. is a distinct species there 

 would be two species. 



1. P. pulicaria Fall. 



1816. Fall. Dipt. Svec. Emp. 33, 44 (Empis). — 1838. Zett. Ins. Lapp. 

 534, 3 [Cyrtoma) et 1842. Dipt. Scand. I, 332, 1. — 1862. Schin. F. A. I, 242. — 

 1901. Verr. Brit. FL VIII, 20, 1, figs. 39—41. — 1907. Kat. palåarkt. Dipt. 

 III, 183. — 1910. Wahlgr. Entom. Tidsskr. 230. 



Male. Vertex and frons black, Occiput black, with black hairs, 

 longest below. Antennæ black or blackish. Thorax black and shining, 

 rather covered with bristles, but otherwise almost bare. Pleura bare, 

 a little pruinose,not shining. Abdomen black, a little pruinose, dullish; 

 it is clothed, but not densely with black hairs, and has long bristles 

 at the hind margins to the segments, longest towards base. Legs 

 yellowish brown or brown, femora and hind legs the darkest; hind 

 tibiæ considerably dilated towards apex, and hind metatarsus a 

 little thickened; the legs are clothed with black hairs, somewhat 

 erect and forming fringes on dorsal side of tibiæ, and above and 

 below femora, on hind femora specially long; middle tibiæ besides 

 with a couple of anterodorsal bristles. Wings somewhat brownish 

 tinged, stigma dark brown ; veins blackish brown. Squamulæ quite 

 sm.all, brown. Halteres blackish brown. 



Female. I do not know the female ; according to the descrip- 

 tions it has the eyes widely separated, frons black and shining 

 and with two or three bristles on each side. 



Length scarcely 2 mm, 



P. pulicaria is very rare in Denmark, I have taken only one 

 specimen, a male, on Bogø south of Sealand on ^/^ 1917. 



